Crime
Laboratories
Forensic Science Services
Crime Labs in the U.S.
▪ Wide Variation in services offered, for
reasons including:
▪ Local laws
▪ Functions of the organization to which the
lab is attached
▪ Budgetary and staffing limitations
Crime Labs in the U.S.
▪ Crime Labs can include:
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Physical Science Unit
Biology Unit
Firearms Unit
Document Examination Unit
Photography Unit
Toxicology Unit
Latent Fingerprint Unit
Voice Analysis Unit
Crime Scene Investigation Unit
Crime Labs in the U.S.
▪ Other Forensic Science Services:
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Forensic Pathology
Forensic Anthropology
Forensic Entomology
Forensic Psychiatry
Forensic Odontology
Forensic Engineering
Forensic Computer and Digital Analysis
Physical Science Unit
▪ Applies techniques of chemistry, physics,
and geology to crime scene examination
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Glass
Paint
Explosives
Soil
Biology Unit
▪ DNA profiling
▪ Blood stains and body fluids
▪ Hair and fiber analysis
▪ Compare botanical materials such as
wood and plants
Firearms Unit
▪ Firearms
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Discharged bullets
Cartridge cases
Shotgun shells
Other ammunition
▪ Garments: examined for firearm
discharge residues
▪ Tool marks
Document Examination Unit
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Examining handwriting and typewriting
Paper and ink analysis
Indented writings, erasures
Burned or charred documents
Photography Unit
▪ Examines and records physical evidence
▪ This may include digital, infrared, UV, and Xray imaging
▪ Prepares photographic exhibits for
courtroom presentation
Toxicology Unit
▪ Examines body fluids and organs for
presence or absence of drugs and
poisons
▪ Often such functions are in a separate
lab under the direction of the medical
examiner or coroner’s office
Fingerprint Unit
▪ Develop latent fingerprints
▪ May take fingerprints of suspects,
persons of interest
▪ Analyze fingerprint ridge characteristics
Other Services
▪ Polygraph
▪ A tool of the criminal investigator rather than
the forensic scientist
▪ Voiceprint Analysis
▪ Telephoned threats, tape-recorded
messages, etc.
▪ Not always considered a valid means of
identification.
Crime-scene Investigation
Unit
▪ This is often under the jurisdiction
of the law enforcement agency.
▪ This unit dispatches specially
trained personnel (police and/or
civilian) to the crime scene to
collect and preserve physical
evidence for later lab analysis.
Working Together…